Apparatus for replacing cathodes



Oct. 22, 1940.

lK. KR'AusE APPARATUS FOR REPLACING CATHODE Filed May 15, 1940 '8f M1 Wfl Patented Oct. 22, 1940 ziert PATENT-OFFICE i lAPPAIm'rUs Fon REPLACING oA'rHoDEs Karl Krause, Berlin, Germany Application May 13, 1940, serial'Nu. 334,964 lln Germany February 17, 1939 3 Claims.

,'I'heipresentiinvention relates to electric discharge devices and more specifically pertains to means for replacing cathodes of electrical discharge tubes Without disturbing the pressure therein.

In a prior arrangement va rod-shaped cathode carrier is fitted in a guide member so that the rod can be easily removed therein. The guide member is sealed with respect to an insulating jacket or housing and extends into the discharge tube formed by the housing.r The housing is sealed externally by a packing on the outer end of the guide member. cathodes is eiected in such a manner that when the packing is loosened, the cathode rod may be withdrawn and provided with a new cathode and re-inserted in the guide member whereupon the packing is tightened. By such an arrangement cathodes can be replaced in a simple manner in a comparatively short period without dismantling parts of the tube and without the operationof the discharge apparatus being interrupted for a long period. Such an arrangement however pro-v vides the disadvantage that the vacuum of the tube is disturbed or lost during the replacement of the cathode. y

'I'he present invention,which is based on the fundamental principle of replacing the cathode includes an arrangement wherein the cathode supporting rod is tted in a guide member and is easily movable therein. The present invention however avoids the disadvantage hereinabove referred to and renders possible the replacement of cathodes without affecting the pressure of the electrical discharge apparatus. The means and the operation of the invention is hereinafter described with reference to the accompanying drawing.

The single iigure of the drawing is a sectional view of apparatus embodying the invention.

A tube 3 is secured at its lower end to a solid spherical member 4. The tube 3 may be attached to the ball 4 in a suitable manner such as by threads 3a. The ball 4 is provided in the direction of the guide member 3 with an opening for the passage of a cathode supporting rod I. The spherical member 4 is surrounded bya two-part casing or housing Ilfin 'which the ball is tightly fitted. The lower part 5 of the casing is provided with two sockets 6 and 8. The socket 3 forms an extension of the guiding means for the cathode supporting rod I in the direction of the tube 3 and the socket 6 communicates with the in- 55 terior of a discharge tube '1. The other socket 8 'Ihe replacement of the is arranged laterally of;v the'socketv 6 and serves for replacing the .cathodes.

The upper part of the casing ory housing 9 is designed as a cap nut and is secured to the lower part 5 in any suitable manner such as by means 5 of threads 9a and even welded to the part 5. A cylindrical resilient member such as a bellows I0 is preferably welded to the casing or housing 9. The other end of the bellows I0 is connected in a vacuum-tight manner to the upper part of the 10 tube 3 by means of a closure disc II which surrounds the tube 3 and is sealed with respect thereto as indicated at Ila. y

The guide member .or tube y3 is closed at the upper end thereof by a conical member I4 pro- 15 vided with a hand wheel I3. The conical member I4 is provided with an extension providing a threaded spindle. I5 engaging threads of the hol-y low cathode supporting rod I so that when the hand wheel I3 is rotated the cathode carrier I is 20` moved in the guide member 3.

If a cathode replacement is to be made the hollow cathode supporting rod I is moved from the position indicated in dotted lines to the position shown in full lines by turning the hand wheel 25 I3. The guide member 3 with the cathode supporting rod I and including the yielding resilient member I0 are now swung out of the axis of the socket 6 into the axisof the socket B. For this purpose a slot I 6 is provided in the casing or 30 housing 9. By the movement of the threaded spindle I5 the cathode supporting 'rod I is inserted in the socket `Il. After loosening the plate I2, the used cathoder 2 is removed and replaced by a new one. In reverse order, the cathode sup- 35 porting rod is reinserted with a new cathode 2 in the guide socket 6 and moved-at a suitable distance from the anode I'I.

By moving the lvacuum--tight connected resilient member I0 it is therefore possible to re- 40 place cathodes without destroying the vacuum of the discharge apparatus.

While the invention has been described with reference to specic structural details it will be appreciated that changes may be madetherein by those skilled in the art. Such changes may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim:

l. Apparatus for removing and replacing a cathode of an electrical discharge tube having a sealed housing comprising, a spherical-shaped casing having a socket sealed with respect to said housing, a spherical member tting tightly with- '55 in said casing, said spherical member having an opening therethrough, a guide member secured to said spherical member and extending therefrom in alignment with said opening, a cathode supporting rod iittirig Within said guide member and movable therein, a second socket carried by said casing arranged at an angle with respect to the first socket, and a resilient member sealing said casing with respect to said guide member.

2. Apparatus for removing and replacing a cathode of an electrical discharge tube having a sealed housing comprising, a spherical-shaped casing having a socket sealed with respect to said housing, a spherical member fitting tightly within said casing, said spherical member having an opening therethrough, a guide member secured to said spherical member and extending therefrom in alignment With said opening, a cathode supporting rod tting Within said guide member and movable therein, said casing having an opening therein arrangedfat an angle with respect to a cathode supporting rod fitting within said guide member and movable therein, a second socket carried by said casing arranged at an angle with respect to the rst socket, said casing having a slot therein for permitting swinging movement of said guide member, and a resilient member sealing said casing with respect to said guide member.

y KARL KRAUSE'. 

